What is the first error he made in computing the standard deviation?

a. yuri failed to find the difference between each data point and the mean.

b. yuri divided by n instead of n -1.

c. yuri did not subtract 9 - 14 correctly.

d. yuri failed to square -2 correctly.

Step-by-step explanation:

Given is a sample with 4 items as

12,9,14,21

Mean = average of 4 = 14

s is the square root of sample variance

Sample variance is the sum of squares divided by n-1

But Yuri divided by 4 = n instead of 3 = n-1

That is the only mistake he did and all other steps are right.

answer: d. $20

step-by-step explanation:

just took the test

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.